نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه شیلات، دانشکده کشاورزی و منابع طبیعی، دانشگاه گنبدکاووس، گنبدکاووس، ایران
2 مرکز تحقیقات ذخایر آب های داخلی، موسسه تحقیقات علوم شیلاتی کشور، سازمان تحقیقات، آموزش و ترویج کشاورزی، گرگان، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
This study was carried out to investigate population dynamic of Caspian roach (R. caspicus) on the south east Caspian Sea in 2018 (In the 6 months of the catch season). A total of 215 samples were collected using beach siene (Total length with 0.01 accuracy and total weight with accuracy of 0.001 were measured). The length of samples range from 16.74 to 30.03 cm and weighing from 52 to 346 gr. The age of the specimens was ranges from 3+ to 7+. Length-weight relationship was W=0.009L3.09, indicating positive allometric growth for population. After fitting the regression using least square method, the relationship was W=0.009L3.42. The Von Bertalanfy growth equation as, Lt=37.1033(1-EXP (-0.19(t+0.40)) . Natural mortality using Pauly's experimental equation calculated as 0.445. The highest condition factor and growth rate was 0.42 and 0.44 respectively, for population in the south east Caspian Sea. Overall, the Caspian roach stocks in the southeastern part of the Caspian Sea appear to be in serious danger and require effective management strategies to maintain their reserves.
کلیدواژهها [English]